Bookwyrm kinda sucks for my taste - no statistics, visuals, tag/genre clouds, limited options for communication, strange UI/UX, etc.
I'll poke around some more, but it seems StoryGraph would do a thing for now.
Mongol king wanted to do our own stuff with a recommendation engine though! I'll help her do it when we escape the yoke of her stupid CEO and my no-work stuck-up situation, I guess.